Dicranura vinula, and other Notes. ALTE 
preferable to the former term, conveys an entirely mis- 
leading idea as to the true position in the prothoracic 
segment. 
Klemensiewicz (8) has already given a very full de- 
scription and figure of the gland and its appendages, 
while in this country Poulton (12, 13) has described and 
figured the external appearances. ‘The existence of this 
gland has long been known, but the literature dealing 
with it and with analogous structures appears to be so 
little known in this country that I have thought it 
advisable to give a short history of the work that has 
been done, and to append a bibliographic lst to this 
paper. 
De Geer (3). It is very singular that the work of 
this author has been so very generally overlooked. I 
have found no mention of him in any of the authorities 
cited, yet so long as one hundred and fifty years ago— 
1745 and 1746—the main features of the organ now under 
discussion were accurately described. De Geer does not 
name his species, but describes it as ‘la Chenille a 
double queue du Saule.” He points out and figures the 
exact position of the aperture of the gland, the existence 
of “le reservoir intérieur,” the power of ejecting the 
liquid to a distance, the freedom of the sac from all but 
tracheal attachments and that of its duct, and the presence 
of two pairs of eversible lateral tubes covered all over with 
“un grand nombre de poils courts.” These lateral tubes, 
however, he fancies to be perforated by numerous minute 
holes, appearing similar to the “ rose” of a watering-can, 
and suggests, though confesses he has not seen the pro- 
cess, that the fluid is ejected through these foramina. 
He also mentions the irritating nature of the fluid, hav- 
ing received part of a discharge “dans mon ceil droit, ot 
cette liqneur me causait d’abord une douleur cuisante et 
comme ardente mais qui, 2 ma grande satisfaction, ne 
duroit pas longtemps.” The defensive value of the 
apparatus is mentioned, and its “ odeur tres forte et péné- 
trante, entiérement semblable a celle de la liqueur que 
jettent les grands Fourmis des bois.” 
Very full details are given as to the habits of the 
larva in using this gland, and it is clear that this early 
author made a very complete study of the subject. I am 
indebted to Professor Poulton for directing my attention 
to de Geer’s work, and to my friend Mr. W. Hatchett 
